U3DXT mail anything issue

Hello there thank you for the great plugin. i use them (socials) all the time in my apps.

however i got one issue: i need to send an pdf file using the mail anything.cs
i could not figure out where to store the pdf file in unity (StreamingAssets folder or something else??). And ofcourse what part do i need to change in the mailanything.cs?

please help me.

Thank you

This could be helpful: